Protecting software environment in isolated execution

ABSTRACT

The present invention is a method and apparatus to protect a subset of a software environment. A key generator generates an operating system nub key (OSNK). The OSNK is unique to an operating system (OS) nub. The OS nub is part of an operating system in a secure platform. A usage protector uses the OSNK to protect usage of a subset of the software environment.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.09/540,946 filed Mar. 31, 2000.

BACKGROUND

1. Field of the Invention

This invention relates to microprocessors. In particular, the inventionrelates to processor security.

2. Description of Related Art

Advances in microprocessor and communication technologies have opened upmany opportunities for applications that go beyond the traditional waysof doing business. Electronic commerce (E-commerce) andbusiness-to-business (B2B) transactions are now becoming popular,reaching the global markets at a fast rate. Unfortunately, while modemmicroprocessor systems provide users convenient and efficient methods ofdoing business, communicating and transacting, they are also vulnerableto unscrupulous attacks. Examples of these attacks include virus,intrusion, security breach, and tampering, to name a few. Computersecurity, therefore, is becoming more and more important to protect theintegrity of the computer systems and increase the trust of users.

Threats caused by unscrupulous attacks may be in a number of forms.Attacks may be remote without requiring physical accesses. An invasiveremote-launched attack by hackers may disrupt the normal operation of asystem connected to thousands or even millions of users. A virus programmay corrupt code and/or data of a single-user platform.

Existing techniques to protect against attacks have a number ofdrawbacks. Anti-virus programs can only scan and detect known viruses.Most anti-virus programs use a weak policy in which a file or program isassumed good until proved bad. For many security applications, this weakpolicy may not be appropriate. In addition, most anti-virus programs areused locally where they are resident in the platform. This may not besuitable in a group work environment. Security co-processors or smartcards using cryptographic or other security techniques have limitationsin speed performance, memory capacity, and flexibility. Redesigningoperating systems creates software compatibility issues and causestremendous investment in development efforts.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present invention will becomeapparent from the following detailed description of the presentinvention in which:

FIG. 1A is a diagram illustrating a logical operating architectureaccording to one embodiment of the invention.

FIG. 1B is a diagram illustrating accessibility of various elements inthe operating system and the processor according to one embodiment ofthe invention.

FIG. 1C is a diagram illustrating a computer system in which oneembodiment of the invention can be practiced.

FIG. 2 is a diagram illustrating a secure platform according to oneembodiment of the invention.

FIG. 3A is a diagram illustrating a subset of a software environmenthaving a usage protector according to one embodiment of the invention.

FIG. 3B is a diagram illustrating a subset of a software environmenthaving a usage protector according to another embodiment of theinvention.

FIG. 3C is a diagram illustrating the subset of a software environmentaccording to yet another embodiment of the invention.

FIG. 3D is a diagram illustrating the subset of a software environmentaccording to yet another embodiment of the invention.

FIG. 3E is a diagram illustrating the subset of a software environmentaccording to yet another embodiment of the invention.

FIG. 4 is a flowchart illustrating a process to protect usage of asubset of a software environment according to one embodiment of theinvention.

FIG. 5 is a flowchart illustrating the process to protect usage of thesubset according to another embodiment of the invention.

FIG. 6 is a flowchart illustrating the process to protect usage of thesubset according to yet another embodiment of the invention.

FIG. 7 is a flowchart illustrating a process to protect usage of thesubset according to yet another embodiment of the invention.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe present invention. However, it will be apparent to one skilled inthe art that these specific details are not required in order topractice the present invention. In other instances, well-knownelectrical structures and circuits are shown in block diagram form inorder not to obscure the present invention.

Architecture Overview

One principle for providing security in a computer system or platform isthe concept of an isolated execution architecture. The isolatedexecution architecture includes logical and physical definitions ofhardware and software components that interact directly or indirectlywith an operating system of the computer system or platform. Anoperating system and the processor may have several levels of hierarchy,referred to as rings, corresponding to various operational modes. A ringis a logical division of hardware and software components that aredesigned to perform dedicated tasks within the operating system. Thedivision is typically based on the degree or level of privilege, namely,the ability to make changes to the platform. For example, a ring-0 isthe innermost ring, being at the highest level of the hierarchy. Ring-0encompasses the most critical, privileged components. In addition,modules in Ring-0 can also access to lesser privileged data, but notvice versa. Ring-3 is the outermost ring, being at the lowest level ofthe hierarchy. Ring-3 typically encompasses users or applications leveland has the least privilege. Ring-1 and ring-2 represent theintermediate rings with decreasing levels of privilege.

FIG. 1A is a diagram illustrating a logical operating architecture 50according to one embodiment of the invention. The logical operatingarchitecture 50 is an abstraction of the components of an operatingsystem and the processor. The logical operating architecture 50 includesring-0 10, ring-1 20, ring-2 30, ring-3 40, and a processor nub loader52. The processor nub loader 52 is an instance of an processor executive(PE) handler. The PE handler is used to handle and/or manage a processorexecutive (PE) as will be discussed later. The logical operatingarchitecture 50 has two modes of operation: normal execution mode andisolated execution mode. Each ring in the logical operating architecture50 can operate in both modes. The processor nub loader 52 operates onlyin the isolated execution mode.

Ring-0 10 includes two portions: a normal execution Ring-0 11 and anisolated execution Ring-0 15. The normal execution Ring-0 11 includessoftware modules that are critical for the operating system, usuallyreferred to as kernel. These software modules include primary operatingsystem (e.g., kernel) 12, software drivers 13, and hardware drivers 14.The isolated execution Ring-0 15 includes an operating system (OS) nub16 and a processor nub 18. The OS nub 16 and the processor nub 18 areinstances of an OS executive (OSE) and processor executive (PE),respectively. The OSE and the PE are part of executive entities thatoperate in a secure environment associated with the isolated area 70 andthe isolated execution mode. The processor nub loader 52 is a protectedbootstrap loader code held within a chipset in the system and isresponsible for loading the processor nub 18 from the processor orchipset into an isolated area as will be explained later.

Similarly, ring-1 20, ring-2 30, and ring-3 40 include normal executionring-1 21, ring-2 31, ring-3 41, and isolated execution ring-1 25,ring-2 35, and ring-3 45, respectively. In particular, normal executionring-3 includes N applications 42 ₁ to 42 _(N) and isolated executionring-3 includes K applets 46 ₁ to 46 _(K).

One concept of the isolated execution architecture is the creation of anisolated region in the system memory, referred to as an isolated area,which is protected by both the processor and chipset in the computersystem. The isolated region may also be in cache memory, protected by atranslation look aside (TLB) access check. Access to this isolatedregion is permitted only from a front side bus (FSB) of the processor,using special bus (e.g., memory read and write) cycles, referred to asisolated read and write cycles. The special bus cycles are also used forsnooping. The isolated read and write cycles are issued by the processorexecuting in an isolated execution mode. The isolated execution mode isinitialized using a privileged instruction in the processor, combinedwith the processor nub loader 52. The processor nub loader 52 verifiesand loads a ring-0 nub software module (e.g., processor nub 18) into theisolated area. The processor nub 18 provides hardware-related servicesfor the isolated execution.

One task of the processor nub 18 is to verify and load the ring-0 OS nub16 into the isolated area, and to generate the root of a key hierarchyunique to a combination of the platform, the processor nub 18, and theoperating system nub 16. The operating system nub 16 provides links toservices in the primary OS 12 (e.g., the unprotected segments of theoperating system), provides page management within the isolated area,and has the responsibility for loading ring-3 application modules 45,including applets 46 ₁ to 46 _(K), into protected pages allocated in theisolated area. The operating system nub 16 may also load ring-0supporting modules.

The operating system nub 16 may choose to support paging of data betweenthe isolated area and ordinary (e.g., non-isolated) memory. If so, thenthe operating system nub 16 is also responsible for encrypting andhashing the isolated area pages before evicting the page to the ordinarymemory, and for checking the page contents upon restoration of the page.The isolated mode applets 46 ₁ to 46 _(K) and their data aretamper-resistant and monitor-resistant from all software attacks fromother applets, as well as from non-isolated-space applications (e.g., 42₁ to 42 _(N)), dynamic link libraries (DLLs), drivers and even theprimary operating system 12. Only the processor nub 18 or the operatingsystem nub 16 can interfere with or monitor the applet's execution.

FIG. 1B is a diagram illustrating accessibility of various elements inthe operating system 10 and the processor according to one embodiment ofthe invention. For illustration purposes, only elements of ring-0 10 andring-3 40 are shown. The various elements in the logical operatingarchitecture 50 access an accessible physical memory 60 according totheir ring hierarchy and the execution mode. The accessible physicalmemory 60 includes an isolated area 70 and a non-isolated area 80. Theisolated area 70 includes applet pages 72 and nub pages 74. Thenon-isolated area 80 includes application pages 82 and operating systempages 84. The isolated area 70 is accessible only to elements of theoperating system and processor operating in isolated execution mode. Thenon-isolated area 80 is accessible to all elements of the ring-0operating system and to the processor.

The normal execution ring-0 11 including the primary OS 12, the softwaredrivers 13, and the hardware drivers 14, can access both the OS pages 84and the application pages 82. The normal execution ring-3, includingapplications 42 ₁ to 42 _(N), can access only to the application pages82. Both the normal execution ring-0 11 and ring-3 41, however, cannotaccess the isolated area 70.

The isolated execution ring-0 15, including the OS nub 16 and theprocessor nub 18, can access to both of the isolated area 70, includingthe applet pages 72 and the nub pages 74, and the non-isolated area 80,including the application pages 82 and the OS pages 84. The isolatedexecution ring-3 45, including applets 46 ₁ to 46 _(K), can access onlyto the application pages 82 and the applet pages 72. The applets 46 ₁ to46 _(K) reside in the isolated area 70.

FIG. 1C is a diagram illustrating a computer system 100 in which oneembodiment of the invention can be practiced. The computer system 100includes a processor 110, a host bus 120, a memory controller hub (MCH)130, a system memory 140, an input/output controller hub (ICH) 150, anon-volatile memory, or system flash, 160, a mass storage device 170,input/output devices 175, a token bus 180, a motherboard (MB) token 182,a reader 184, and a token 186. The MCH 130 may be integrated into achipset that integrates multiple functionalities such as the isolatedexecution mode, host-to-peripheral bus interface, memory control.Similarly, the ICH 150 may also be integrated into a chipset together orseparate from the MCH 130 to perform I/O functions. For clarity, not allthe peripheral buses are shown. It is contemplated that the system 100may also include peripheral buses such as Peripheral ComponentInterconnect (PCI), accelerated graphics port (AGP), Industry StandardArchitecture (ISA) bus, and Universal Serial Bus (USB), etc.

The processor 110 represents a central processing unit of any type ofarchitecture, such as complex instruction set computers (CISC), reducedinstruction set computers (RISC), very long instruction word (VLIW), orhybrid architecture. In one embodiment, the processor 110 is compatiblewith an Intel Architecture (IA) processor, such as the Pentium series,the IA-32™ and the IA-64™. The processor 110 includes a normal executionmode 112 and an isolated execution circuit 115. The normal executionmode 112 is the mode in which the processor 110 operates in a non-secureenvironment, or a normal environment without the security featuresprovided by the isolated execution mode. The isolated execution circuit115 provides a mechanism to allow the processor 110 to operate in anisolated execution mode. The isolated execution circuit 115 provideshardware and software support for the isolated execution mode. Thissupport includes configuration for isolated execution, definition of anisolated area, definition (e.g., decoding and execution) of isolatedinstructions, generation of isolated access bus cycles, and generationof isolated mode interrupts.

In one embodiment, the computer system 100 can be a single processorsystem, such as a desktop computer, which has only one main centralprocessing unit, e.g. processor 110. In other embodiments, the computersystem 100 can include multiple processors, e.g. processors 110, 110 a,110 b, etc., as shown in FIG. 1C. Thus, the computer system 100 can be amulti-processor computer system having any number of processors. Forexample, the multi-processor computer system 100 can operate as part ofa server or workstation environment. The basic description and operationof processor 110 will be discussed in detail below. It will beappreciated by those skilled in the art that the basic description andoperation of processor 110 applies to the other processors 110 a and 110b, shown in FIG. 1C, as well as any number of other processors that maybe utilized in the multi-processor computer system 100 according to oneembodiment of the present invention.

The processor 110 may also have multiple logical processors. A logicalprocessor, sometimes referred to as a thread, is a functional unitwithin a physical processor having an architectural state and physicalresources allocated according to some partitioning policy. Within thecontext of the present invention, the terms “thread” and “logicalprocessor” are used to mean the same thing. A multi-threaded processoris a processor having multiple threads or multiple logical processors. Amulti-processor system (e.g., the system comprising the processors 110,110 a, and 110 b) may have multiple multi-threaded processors.

The host bus 120 provides interface signals to allow the processor 110or processors 110, 100 a, and 110 b to communicate with other processorsor devices, e.g., the MCH 130. In addition to normal mode, the host bus120 provides an isolated access bus mode with corresponding interfacesignals for memory read and write cycles when the processor 110 isconfigured in the isolated execution mode. The isolated access bus modeis asserted on memory accesses initiated while the processor 110 is inthe isolated execution mode. The isolated access bus mode is alsoasserted on instruction pre-fetch and cache write-back cycles if theaddress is within the isolated area address range and the processor 110is initialized in the isolated execution mode. The processor 110responds to snoop cycles to a cached address within the isolated areaaddress range if the isolated access bus cycle is asserted and theprocessor 110 is initialized into the isolated execution mode.

The MCH 130 provides control and configuration of memory andinput/output devices such as the system memory 140 and the ICH 150. TheMCH 130 provides interface circuits to recognize and service isolatedaccess assertions on memory reference bus cycles, including isolatedmemory read and write cycles. In addition, the MCH 130 has memory rangeregisters (e.g., base and length registers) to represent the isolatedarea in the system memory 140. Once configured, the MCH 130 aborts anyaccess to the isolated area that does not have the isolated access busmode asserted.

The system memory 140 stores system code and data. The system memory 140is typically implemented with dynamic random access memory (DRAM) orstatic random access memory (SRAM). The system memory 140 includes theaccessible physical memory 60 (shown in FIG. 11B). The accessiblephysical memory includes a loaded operating system 142, the isolatedarea 70 (shown in FIG. 1B), and an isolated control and status space148. The loaded operating system 142 is the portion of the operatingsystem that is loaded into the system memory 140. The loaded OS 142 istypically loaded from a mass storage device via some boot code in a bootstorage such as a boot read only memory (ROM). The isolated area 70, asshown in FIG. 1B, is the memory area that is defined by the processor110 when operating in the isolated execution mode. Access to theisolated area 70 is restricted and is enforced by the processor 110and/or the MCH 130 or other chipset that integrates the isolated areafunctionalities. The isolated control and status space 148 is aninput/output (I/O)-like, independent address space defined by theprocessor 110 and/or the MCH 130. The isolated control and status space148 contains mainly the isolated execution control and status registers.The isolated control and status space 148 does not overlap any existingaddress space and is accessed using the isolated bus cycles. The systemmemory 140 may also include other programs or data which are not shown.

The ICH 150 represents a known single point in the system having theisolated execution functionality. For clarity, only one ICH 150 isshown. The system 100 may have many ICH's similar to the ICH 150. Whenthere are multiple ICH's, a designated ICH is selected to control theisolated area configuration and status. In one embodiment, thisselection is performed by an external strapping pin. As is known by oneskilled in the art, other methods of selecting can be used, includingusing programmable configuring registers. The ICH 150 has a number offunctionalities that are designed to support the isolated execution modein addition to the traditional I/O functions. In particular, the ICH 150includes an isolated bus cycle interface 152, the processor nub loader52 (shown in FIG. 1A), a digest memory 154, a cryptographic key storage155, an isolated execution logical processor manager 156, and a tokenbus interface 159.

The isolated bus cycle interface 152 includes circuitry to interface tothe isolated bus cycle signals to recognize and service isolated buscycles, such as the isolated read and write bus cycles. The processornub loader 52, as shown in FIG. 1A, includes a processor nub loader codeand its digest (e.g., hash) value. The processor nub loader 52 isinvoked by execution of an appropriate isolated instruction (e.g.,Iso_Init) and is transferred to the isolated area 70. From the isolatedarea 80, the processor nub loader 52 copies the processor nub 18 fromthe system flash memory (e.g., the processor nub code 18 in non-volatilememory 160) into the isolated area 70, verifies and logs its integrity,and manages a symmetric key used to protect the processor nub's secrets.In one embodiment, the processor nub loader 52 is implemented in readonly memory (ROM). For security purposes, the processor nub loader 52 isunchanging, tamper-resistant and non-substitutable. The digest memory154, typically implemented in RAM, stores the digest (e.g., hash) valuesof the loaded processor nub 18, the operating system nub 16, and anyother critical modules (e.g., ring-0 modules) loaded into the isolatedexecution space. The cryptographic key storage 155 holds a symmetricencryption/decryption key that is unique for the platform of the system100. In one embodiment, the cryptographic key storage 155 includesinternal fuses that are programmed at manufacturing. Alternatively, thecryptographic key storage 155 may also be created with a random numbergenerator and a strap of a pin. The isolated execution logical processormanager 156 manages the operation of logical processors operating inisolated execution mode. In one embodiment, the isolated executionlogical processor manager 156 includes a logical processor countregister that tracks the number of logical processors participating inthe isolated execution mode. The token bus interface 159 interfaces tothe token bus 180. A combination of the processor nub loader digest, theprocessor nub digest, the operating system nub digest, and optionallyadditional digests, represents the overall isolated execution digest,referred to as isolated digest. The isolated digest is a fingerprintidentifying the ring-0 code controlling the isolated executionconfiguration and operation. The isolated digest is used to attest orprove the state of the current isolated execution.

The non-volatile memory 160 stores non-volatile information. Typically,the non-volatile memory 160 is implemented in flash memory. Thenon-volatile memory 160 includes the processor nub 18. The processor nub18 provides the initial set-up and low-level management of the isolatedarea 70 (in the system memory 140), including verification, loading, andlogging of the operating system nub 16, and the management of thesymmetric key used to protect the operating system nub's secrets. Theprocessor nub 18 may also provide application programming interface(API) abstractions to low-level security services provided by otherhardware. The processor nub 18 may also be distributed by the originalequipment manufacturer (OEM) or operating system vendor (OSV) via a bootdisk.

The mass storage device 170 stores archive information such as code(e.g., processor nub 18), programs, files, data, applications (e.g.,applications 42 ₁ to 42 _(N)), applets (e.g., applets 46 ₁ to 46 _(K))and operating systems. The mass storage device 170 may include compactdisk (CD) ROM 172, floppy diskettes 174, and hard drive 176, and anyother magnetic or optical storage devices. The mass storage device 170provides a mechanism to read machine-readable media. When implemented insoftware, the elements of the present invention are the code segments toperform the necessary tasks. The program or code segments can be storedin a processor readable medium or transmitted by a computer data signalembodied in a carrier wave, or a signal modulated by a carrier, over atransmission medium. The “processor readable medium” may include anymedium that can store or transfer information. Examples of the processorreadable medium include an electronic circuit, a semiconductor memorydevice, a ROM, a flash memory, an erasable programmable ROM (EPROM), afloppy diskette, a compact disk CD-ROM, an optical disk, a hard disk, afiber optical medium, a radio frequency (RF) link, etc. The computerdata signal may include any signal that can propagate over atransmission medium such as electronic network channels, optical fibers,air, electromagnetic, RF links, etc. The code segments may be downloadedvia computer networks such as the Internet, an Intranet, etc.

I/O devices 175 may include any I/O devices to perform I/O functions.Examples of I/O devices 175 include a controller for input devices(e.g., keyboard, mouse, trackball, pointing device), media card (e.g.,audio, video, graphics), a network card, and any other peripheralcontrollers.

The token bus 180 provides an interface between the ICH 150 and varioustokens in the system. A token is a device that performs dedicatedinput/output functions with security functionalities. A token hascharacteristics similar to a smart card, including at least onereserved-purpose public/private key pair and the ability to sign datawith the private key. Examples of tokens connected to the token bus 180include a motherboard token 182, a token reader 184, and other portabletokens 186 (e.g., smart card). The token bus interface 159 in the ICH150 connects through the token bus 180 to the ICH 150 and ensures thatwhen commanded to prove the state of the isolated execution, thecorresponding token (e.g., the motherboard token 182, the token 186)signs only valid isolated digest information. For purposes of security,the token should be connected to the digest memory.

Protecting Software Environment in Isolated Execution

The overall architecture discussed above provides a basic insight into ahierarchical executive architecture to manage a secure platform. Theelements shown in FIGS. 1A, 1B, and 1C are instances of an abstractmodel of this hierarchical executive architecture. The implementation ofthis hierarchical executive architecture is a combination of hardwareand software. In what follows, the processor executive, the processorexecutive handler, and the operating system executive are abstractmodels of the processor nub 18, the processor nub loader 52, and theoperating system nub 16 (FIGS. 1A, 1B, and 1C), respectively.

FIG. 2 is a diagram illustrating a secure platform 200 according to oneembodiment of the invention. The secure platform 200 includes the OS nub16, the processor nub 18, a key generator 240, a hashing function 220,and a usage protector 250, all operating within the isolated executionenvironment, as well as a software environment 210 that may exist eitherinside or outside the isolated execution environment.

The OS nub or OS executive (OSE) 16 is part of the operating systemrunning on the secure platform 200. The OS nub 16 has an associated OSnub identifier (ID) 201, that may be delivered with the OS nub 16 orderived from an OS nub code or associated information. The OS nub ID 201may be a pre-determined code that identifies the particular version ofthe OS nub 16. It may also represent a family of various versions of theOS nub 16. The OS nub 16 may optionally have access to a public andprivate key pair unique for the platform 200. The key pair may begenerated and stored at the time of manufacturing, at first system boot,or later. The protected private key 204 may be programmed into the fusesof a cryptographic key storage 155 of the input/output control hub (ICH)150 or elsewhere in persistent storage within the platform 200. Theprotected private key 204 may be based upon a random number generated byan external random number generator. In one embodiment, the protectedprivate key 204 is generated by the platform 200 itself the first timethe platform 200 is powered up. The platform 200 includes a randomnumber generator to create random numbers. When the platform 200 isfirst powered up, a random number is generated upon which the protectedprivate key 204 is based. The protected private key 204 can then bestored in the multiple key storage 164 of the non-volatile flash memory160. The feature of the protected private key 204 is that it cannot becalculated from its associated public key 205. Only the OS nub 16 canretrieve and decrypt the encrypted private key for subsequent use. Inthe digital signature generation process, the protected private key 204is used as an encryption key to encrypt a digest of a message producinga signature, and the public key 205 is used as a decryption key todecrypt the signature, revealing the digest value.

The processor nub 18 includes a master binding key (BK0) 202. The BK0202 is generated at random when the processor nub 18 is first invoked,i.e., when it is first executed on the secure platform 200. The keygenerator 240 generates a key operating system nub key (OSNK) 203 whichis provided only to the OS Nub 16. The OS nub 16 may supply the OSNK 203to trusted agents, such as the usage protector 250. The key generator240 receives the OS Nub identifier 201 and the BK0 202 to generate theOSNK 203. There are a number of ways for the key generator 240 togenerate the OSNK 203. The key generator 240 generates the OSNK 203 bycombining the BK0 202 and the OS Nub ID 201 using a cryptographic hashfunction. In one embodiment, the OS nub ID 201 identifies the OS nub 16being installed into the secure platform 200. The OS nub ID 201 can bethe hash of the OS nub 16, or a hash of a certificate that authenticatesthe OS nub 16, or an ID value extracted from a certificate thatauthenticates the OS nub 16. It is noted that a cryptographic hashfunction is a one-way function, mathematical or otherwise, which takes avariable-length input string, called a pre-image and converts it to afixed-length, generally smaller, output string referred to as a hashvalue. The hash function is one-way in that it is difficult to generatea pre-image that matches the hash value of another pre-image. In oneembodiment, the OS nub ID 201 is a hash value of one of the OS Nub 16and a certificate representing the OS nub 16. Since the security of analgorithm rests in the key, it is important to choose a strongcryptographic process when generating a key. The software environment210 may include a plurality of subsets (e.g., subset 230). The usage ofthe software environment 210 or the usage of the subset 230 is protectedby the usage protector 250. The usage protector 250 uses the OSNK 203 toprotect the usage of the subset 230. The software environment 210 mayinclude an operating system (e.g., a Windows operating system, a Windows95 operating system, a Windows 98 operating system, a Windows NToperating system, Windows 2000 operating system) or a data base. Thesubset 230 may be a registry in the Windows operating system or a subsetof a database. Elements can be implemented in hardware or software.

The subset 230 is hashed by the hashing function 220 to produce a firsthash value 206 and a second hash value 312. One way to detect intrusionor modification of the subset 230 is to compare the state of the subsetbefore and after a time period. The first and second hash values 206 and312 are typically generated at different times and/or at differentplaces.

The usage protector 250 is coupled to the key generator 240 to protectusage of the software environment 210 or the subset 230, using the OSNK203. The usage protection includes protection against unauthorizedreads, and detection of intrusion, tampering or unauthorizedmodification. If the two hash values are not the same, then the usageprotector 250 knows that there is a change in the subset 230. If it isknown that this change is authorized and an updated hash value has beenprovided, the usage protector 250 would merely report the result.Otherwise, the usage protector 250 may generate an error or a faultfunction. When a user is notified of the error, fault condition, he orshe would know that the subset 230 has been tampered, modified. The usermay take appropriate action. Therefore, the usage of the subset 230 isprotected.

The are several different embodiments of the usage protector 250. In oneembodiment, the usage protector 250 decrypts the subset using the OSNK203. In two other embodiments, the usage protector 250 uses not only theOSNK 203 but also the first hash value 206 and the second hash value312. Yet in two other embodiments, the usage protector uses the OSNK203, the protected private key 204 and the pubic key 205.

FIG. 3A is a diagram illustrating the usage protector 250 shown in FIG.2 according to one embodiment of the invention. The usage protector 250includes a compressor 370, an encryptor 375, a storage 380, a decryptor385, and a decompressor 390.

The compressor 370 receives the subset 230 and compresses the subset 230to generate a compressed subset 372. The encryptor 375 then encrypts thecompressed subset 372 using the OSNK 203, producing the encryptedcompressed subset 377. The OSNK 203 is provided to the usage protection250 by the key generator 240 as shown in FIG. 2. At a later time, arequest can be made to the OS nub 16 to access the encrypted compressedsubset 377. If this request is granted, the decryptor 385 decrypts theretrieved encrypted compressed subset 382 using the OSNK 203, producingthe retrieved compressed subset 387. The decompressor 390 then expandsthe retrieved compressed subset 387 to produce the retrieved subset 392.The compression operation is applied to save time (i.e. speed up) and/orspace for storing the subset 230 in a memory. In another embodiment, theencryptor 375 takes the subset 230 without going through the compressingprocess and encrypts the subset 230 to generate an encrypted subsetusing the OSNK 203, and the decryptor 385 decrypts the retrievedencrypted subset directly producing the retrieved subset 392. Theencrypting of the compressed subset 372 or the subset 230 preventsunauthorized reads of the subset 230.

FIG. 3B is a diagram illustrating the usage protector 250 shown in FIG.2 according to another embodiment of the invention. The usage protector250 includes an encryptor 305, a decryptor 365, a storage medium 310,and a comparator 315.

The encryptor 305 encrypts the first hash value 206 using the OSNK 203to generate an encrypted first hash value 302. The encrypted first hashvalue 302 is then stored in the storage 310. Storage medium 310 may beany type of medium capable of storing the encrypted hash value 302. Thestorage medium 310 may be, for example, a tape or a disk (e.g., a floppydisk, a hard disk, or an optical disk). At a later time, the subset 230is tested for integrity. The decryptor 365 decrypts the retrievedencrypted first hash value 303 using the OSNK 203. This decryptingprocess generates a decrypted hash value 366. This decrypted first hashvalue 366 is then compared to the second hash value 312 by thecomparator 315 to detect if changes have been made in the subset 230. Ifthe two values match, then subset 230 has not been changed. If thesubset 230 is deliberately updated by an authorized agent, the storedencrypted hash value is also updated, and a subsequent integrity testagain results in the two hash values (366 and 312) matching. If thesubset 230 is modified by an unauthorized agent that does not update thestored encrypted hash value, then the subsequent integrity test resultsin differing hash values 366 and 312, signaling the unauthorizedmodification. The unauthorized agent cannot avoid this detection byattempting to generate its own version of the stored encrypted hashvalue, because the unauthorized agent does not have access to the OSNK203.

FIG. 3C is a diagram illustrating the usage protector 250 shown in FIG.2 according to one embodiment of the invention. The usage protector 250includes a decryptor 325, a signature generator 320, a storage medium322, and a signature verifier 330.

The decryptor 325 accepts the OS nub's encrypted private key (i.e.,protected) 204, and decrypts it using the OSNK 203, exposing the privatekey 328 for use in the isolated environment. The signature generator 320generates a signature 304 for the subset 230 using the private key 328.It is noted that the subset 230 may be compressed before input it intothe signature generator 320 to generate the signature 304. The signaturealgorithm used by the signature generator 320 may be public-key digitalsignature algorithm which makes use of a secret private key to generatethe signature, and a public key to verify the signature. Examplealgorithms include ElGama, Schnorr and Digital Signature Algorithmsschemes just to name a few. In one embodiment, the generation of thesignature 304 includes hashing the subset 230 to generate a before hashvalue, which is then encrypted using the private key 328 to generate thesignature 304. The signature 304 is then saved in a storage medium 322.At a later time, the signature is retrieved from the storage 322, andthe retrieved signature 306 is used, along with public key 205, by thesignature verifier 330 to verify the subset 230. The signature verifier330 verifies whether the subset 230 has been modified, producing amodified/not-modified indicator 331. In one embodiment, the verificationprocess includes decrypting the retrieved signature 306 using the publickey 205 to expose the before hash value. The subset 230 is hashed togenerate an after hash value. The before hash value is compared to theafter hash value to detect whether the subset 230 has been modified. Ifthe two hash values match, the subset 230 is the same as it was when thesignature was generated.

FIG. 3D is a diagram illustrating the usage protector 250 according toyet another embodiment of the invention. The usage protector 250includes a decryptor 345, a manifest generator 335, a signaturegenerator 340, a storage medium 349, a signature verifier 350, and amanifest verifier 355.

The decryptor 345 accepts the OS nub's encrypted protected private key204, and decrypts it using the OSNK 203, exposing the private key 348for use in the isolated environment. The manifest generator 335generates a manifest 307 for the subset 230. The manifest 307 representsthe subset 230 in a concise manner. The manifest 307 may include anumber of descriptors or entities, which characterize some relevantaspects of the subset 230. Typically, these relevant aspects areparticular or specific to the subset 230 so that two different subsetshave different manifests. In one embodiment, the manifest 307 representsa plurality of entities (i.e., a collection of entities) where eachentry in the manifest 307 represents a hash (e.g., unique fingerprint)over one entity in the collection. The subset 230 is partitioned intoone or more group where each group has a pointer and associated hash inthe manifest 307. The manifest 307 is stored in a storage medium 349 forlater use. The manifest 307 is also input to the signature generator 340to generate a signature 308 over the manifest 307 using the private key348. The generated signature 308 is also stored in a storage medium 349.At a later time, we desire to verify that the portions of the subset 230described by the manifest have not changed. This requires verifying thatthe manifest itself has not been changed, and that each group in subset230 described by the manifest has not been changed. The stored signatureand manifest are retrieved from the storage medium 349. The retrievedsignature 309, and the retrieved manifest 354, along with the public key205, are used by the signature verifier 350 to test that the retrievedmanifest 354 is unchanged from the original manifest 307. The signatureverifier 350 produces a signature-verified flag 351, which is assertedonly if the signature verifies that the manifest is unchanged. In oneembodiment, the verification process includes decrypting the retrievedsignature 309 using the public key 205 to expose the before hash value.The retrieved manifest 354 is hashed to generate an after hash value.The before hash value is compared to the after hash value to detectwhether the retrieved manifest 354 has been modified. If the two hashvalues match, the retrieved manifest 354 is the same as it was when thesignature was generated. The retrieved manifest 354 is also supplied tothe manifest verifier 355, which uses the descriptive information in theretrieved manifest 354 to selectively verify portions of subset 230. Ina typical embodiment, this involves hashing each group in subset 230,where the group is identified by information in the retrieved manifest354, and comparing the newly generated hash value against the hash valuefor the group stored in the retrieved manifest 354. The manifestverifier 355 produces a manifest-verified flag 356, which is asserted ifall entries described by the retrieved manifest 354 are verified asunchanged. If both the manifest-verified flag and the signature-verifiedflag are asserted, then the overall verification process passes, and theselected portions of subset 230 are known to be the same as when thesigned manifest was originally generated, and a pass/fail flag 358 isasserted. Note that the signature verifier 350 and the manifest verifier355 can be invoked in any order.

FIG. 3E is a diagram illustrating the usage protector 250 shown in FIG.2 according to another embodiment of the invention. The usage protector250 includes a first encryptor 305, a second encryptor 311, a storagemedium 310, and a comparator 315.

The first encryptor 305 encrypts the first hash value 206 using the OSNK203. The first hash value 206 is provided by the hashing function 220 asshown in FIG. 2. The first encryptor 305 takes the first hash value 206and encrypts it to generate an encrypted first hash value 302 using theOSNK 203. The encrypted hash value 302 is then stored in a storage 310for later use. The encryption by the OSNK 203 allows the encrypted firsthash value 302 to be stored in arbitrary (i.e., unprotected) storagemedia. Storage medium 310 may be any type of medium capable of storinginformation (e.g., the encrypted hash value 302). The storage medium 310may be, for example, a tape or a disk (e.g., a floppy disk, a hard disk,or an optical disk). The second encryptor 365 311 encrypts the secondhash value 312 to generate an encrypted second hash value 301 using theOSNK 203. The second hash value 312 is provided by the hash function220. The first encryptor 305 and the second encryptor 311 use the sameencryption algorithm, and this algorithm produces identical repeatableresults for a given input. The encrypted first hash value 302 is nowretrieved from the storage 310 for comparing with the encrypted secondhash value 301. The comparator 315 compares the encrypted second hashvalue 301 with the retrieved encrypted first hash value 303 to detect ifthe subset 230 has been modified or tampered with. In the case where thesubset 230 is deliberately updated by an authorized agent, the storedencrypted hash value is also updated. Since the modification of thesubset 230 is authorized, the second encrypted hash value 301 is thesame as the retrieved first encrypted first hash value 303. In the casewhere the subset 230 has been unauthorized modified or tampered with,the comparator 315 generates a modified/not-modified flag indicating thesubset 230 has been modified and therefore, the subset 230 should not beused. An attacker cannot simply replace the first encrypted hash value303 with one corresponding to the unauthorized modified subset 230,because the attacker does not have access to the OSNK 203 used toencrypt the hash value.

FIG. 4 is a flowchart illustrating a process 400 to protect usage of thesoftware environment 210 or subset 230 according to one embodiment ofthe invention.

Upon START, the process 400 checks to see whether accessing to thesubset is authorized (Block 405). If accessing to the subset isauthorized, the process 400 is terminated. Otherwise, the process 400checks to see if the accessing to the subset is a read or a write (Block410). If it is a write, the process 400 obtains the OSNK and the subset(Block 415). The process 400 then encrypts the subset using the OSNK(Block 420) and stores the encrypted subset in a storage (Block 425),the process 400 is terminated. If accessing to the subset is a read, theprocess 400 obtains the OSNK and the encrypted subset (Block 430). Theprocess then decrypts the encrypted subset using the OSNK (Block 435),the process 400 is the terminated.

FIG. 5 is a flowchart illustrating a process 500 to protect usage of thesubset of the software environment according to one embodiment of theinvention.

Upon START, the process 500 checks to see whether the subset is to beupdated or to be tested (Block 505). If it is to be updated, the process500 checks to see whether accessing the subset is authorized (Block510). If accessing the subset is not authorized, the process 500 isterminated. If accessing the subset is authorized, the process 500obtains the OSNK and the first hash value (Block 515) and encrypts thefirst hash value using the OSNK (Block 520). The process 500 then storesthe encrypted first hash value in a storage for later use (Block 525).The process is terminated. If the subset is to be tested, the process500 then obtains the OSNK and the second hash value (Block 550). Theprocess 500 also retrieves the encrypted first hash value from thestorage (Block 555) and decrypts it using the OSNK (Block 560). Theprocess 500 then checks to see whether the two hash values are equal(Block 565). If the two hash values are equal, the process 500 clears“modified” flag (Block 570) and is terminated. Otherwise, the process500 sets “modified” flag (Block 575) and is terminated.

FIG. 6 is a flowchart illustrating a process to protect usage of asubset of a software environment according to yet another embodiment ofthe invention.

Upon START, the process 600 checks to see whether the subset is to beupdated or to be tested (Block 605). If it is to be updated, the process600 checks to see whether the request to be updated is authorized (Block610). If it is not authorized, the process 600 is terminated. Otherwise,the process 600 obtains the OSNK, the protected private key and thesubset (Block 615). The process 600 then decrypts the protected privateusing the OSNK (Block 620) and signs the subset using the private key(Block 625). The process 600 stores the signature in a storage (Block630) and is terminated. If the subset is to be tested, the process 600obtains the public key, the subset, and the signature (Block 650). Theprocess 600 verifies the subset against the signature using the publickey (Block 655). The process 600 then checks whether the subset isverified (Block 660). If the subset is verified, the process 600 clears“modified” flag (Block 665) and is terminated. Otherwise, the process600 sets “modified” flag (Block 670) and is terminated.

FIG. 7 is a flowchart illustrating a process 700 to protect usage of asubset of a software environment according to yet another embodiment ofthe invention.

Upon START, the process 700 checks to see whether the subset is to beupdated or tested (Block 705). If it is to be updated, the process 700then checks to see whether the accessing to the subset is authorized(Block 710). If it is not authorized, the process 700 is terminated.Otherwise, the process 700 obtains the OSNK and the first hash value(Block 715) and encrypts the first hash value using the OSNK (Block720). The process then stores the encrypted first hash value in astorage (Block 725) and is terminated. If the subset is to be tested,the process 700 obtains the OSNK and the second hash value (Block 750)and encrypts the second hash value using the OSNK (Block 755). Theprocess 700 then retrieves the encrypted first hash value from thestorage (Block 760) and checks to see whether the encrypted hashes areequal (Block 765). If they are equal, the process 700 clears “modified”flag and is terminated. Otherwise, the process 700 sets “modified” flag(Block 775) and is terminated.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications of the illustrative embodiments,as well as other embodiments of the invention, which are apparent topersons skilled in the art to which the invention pertains are deemed tolie within the spirit and scope of the invention.

1. An apparatus comprising: a key generator to generate an operatingsystem nub key (OSNK) unique to an operating system (OS) nub, the OS nubbeing part of an operating system to run on a platform comprising aprocessor capable of operating in an isolated execution mode in a ring 0operating mode, wherein the processor also supports one or more higherring operating modes, as well as a normal execution mode in at least thering 0 operating mode; and a usage protector coupled to the keygenerator to protect usage of a subset of a software environment usingthe OSNK; the key generator to generate the OSNK based at least in parton a master binding key (BK0) of the platform and an identification ofthe OS nub; wherein the usage protector performs at least one operationselected from the group consisting of: encrypting a value whileoperating in isolated execution mode; and decrypting an encrypted valuewhile operating in isolated execution mode.
 2. The apparatus of claim 1,wherein the identification comprises a hash value of at least one itemselected from the group consisting of the OS nub and a certificaterepresenting the OS nub.
 3. The apparatus of claim 1 wherein the usageprotector comprises: an encryptor to encrypt the subset of the softwareenvironment using the OSNK, the encrypted subset being stored in astorage; and a decryptor to decrypt the encrypted subset using the OSNK,the encrypted subset being retrieved from the storage.
 4. The apparatusof claim 1 wherein the usage protector comprises: an encryptor toencrypt a first hash value of the subset of the software environmentusing the OSNK, the encrypted first hash value being stored in astorage; a decryptor to decrypt the encrypted first hash value using theOSNK, the encrypted first hash value being retrieved from the storage;and a comparator to compare the decrypted first hash value to a secondhash value to generate a compared result, the compared result indicatingwhether the subset of the software environment has been modified.
 5. Theapparatus of claim 1 wherein the usage protector comprises: a firstencryptor to encrypt a first hash value of the subset of the softwareenvironment using the OSNK, the encrypted first hash value being storedin a storage; a second encryptor to encrypt a second hash value usingthe OSNK; and a comparator to compare the encrypted second hash value tothe encrypted first hash value to generate a compared result, theencrypted first hash value being retrieved from the storage, thecompared result indicating whether the subset of the softwareenvironment has been modified.
 6. The apparatus of claim 1 wherein theusage protector comprises: a decryptor to decrypt a protected privatekey to generate a private key using the OSNK; a signature generatorcoupled to the decryptor to generate a signature of the subset of thesoftware environment using the private key, the signature being storedin a storage; and a signature verifier to verify the signature togenerate a modified/not modified flag using a public key, the signaturebeing retrieved from the storage, the modified/not modified flagindicating whether the subset has been modified.
 7. The apparatus ofclaim 1 wherein the usage protector comprises: a manifest generator togenerate a manifest of the subset of the software environment, themanifest describing the subset of the software environment, the manifestbeing stored in a storage; a signature generator coupled to the manifestgenerator to generate a manifest signature using a private key, theprivate key being decrypted by a decryptor using the OSNK, the manifestsignature being stored in the storage; a signature verifier to verifythe manifest signature to generate a signature verified flag using apublic key, the manifest signature being retrieved from the storage; anda manifest verifier to verify the manifest to generate a manifestverified flag, the manifest being retrieved from the storage, themanifest verified flag and the signature verified flag being tested at atest center, the test center generating a pass/fail signal to indicatewhether the subset has been modified.
 8. The apparatus of claim 1wherein the subset of the software environment comprises a registry ofan operating system.
 9. The apparatus of claim 1, wherein the BK0 isgenerated at random on a first invocation of a processor nub.
 10. Amethod comprising: generating an operating system nub key (OSNK) uniqueto an operating system (OS) nub, the OS nub being part of an operatingsystem to run in a software environment on a platform comprising aprocessor capable of operating in an isolated execution mode in a ring 0operating mode, wherein the processor also supports one or more higherring operating modes, as well as a normal execution mode in at least thering 0 operating mode; and protecting usage of a subset of the softwareenvironment using the OSNK; wherein the operation of protecting usage ofa subset of the software environment comprises at least one operationselected from the group consisting of: encrypting a value whileoperating in isolated execution mode; and decrypting an encrypted valuewhile operating in isolated execution mode; and wherein the operation ofgenerating an OSNK comprises generating the OSNK based at least in parton an identification of the OS nub and a master binding key (BK0) of theplatform.
 11. The method of claim 10, wherein the identificationcomprises a hash value of at least one item selected from the groupconsisting of the OS nub and a certificate representing the OS nub. 12.The method of claim 10 wherein protecting usage comprises: encryptingthe subset of the software environment using the OSNK; storing theencrypted subset in a storage; and decrypting the encrypted subset fromthe storage using the OSNK.
 13. The method of claim 10 whereinprotecting usage comprises: encrypting a first hash value of the subsetof the software environment using the OSNK, the encrypted first hashvalue being stored in a storage; decrypting the encrypted first hashvalue of the subset of the software environment using the OSNK, theencrypted first hash value being retrieved from the storage; andcomparing the decrypted first hash value to a second hash value togenerate a compared result, the decrypted first hash value beingretrieved from the storage, the compared result indicating whether thesubset of the software environment has been modified.
 14. The method ofclaim 10 wherein protecting usage comprises: encrypting a first hashvalue of the subset of the software environment using the OSNK, theencrypted first hash value being stored in a storage; encrypting asecond hash value using the OSNK; and comparing the encrypted first hashvalue to the encrypted second hash value to generate a compared result,the encrypted first hash value being retrieved from the storage, thecompared result indicating whether the subset of the softwareenvironment has been modified.
 15. The method of claim 10 whereinprotecting usage comprises: decrypting a protected private key togenerate a private key using the OSNK; generating a signature of thesubset of the software environment using the private key, the signaturebeing stored in a storage; and verifying the signature to generate amodified/not modified flag using a public key, the signature beingretrieved from the storage, the modified/not modified flag indicatingwhether the subset of the software environment has been modified. 16.The method of claim 10 wherein detecting comprises: generating amanifest of the subset of the software environment, the manifestdescribing the subset of the software environment, the manifest beingstored in a storage; generating a manifest signature of the manifestusing a private key, the private key being decrypted using the OSNK, themanifest signature being stored in the storage; verifying the manifestsignature to generate a signature verified flag using a public key, themanifest signature being retrieved from the storage; and verifying themanifest to generate a manifest verified flag, the manifest beingretrieved from the storage, the manifest verified flag and the signatureverified flag being tested at a test center, the test center generatinga pass/fail signal, the pass/fail signal indicating whether the subsetof the software environment has been modified.
 17. The method of claim10 wherein the subset of the software environment comprises a registryof the operating system.
 18. The method of claim 10, wherein the BK0 isgenerated at random on a first invocation of a processor nub.
 19. Acomputer program product comprising: a computer usable medium havingcomputer program code embodied therein, the computer program producthaving: computer readable program code to generate an operating systemnub key (OSNK) unique to an operating system (OS) nub, the OS nub beingpart of an operating system to run in a software environment on aplatform comprising a processor capable of operating in an isolatedexecution mode in a ring 0 operating mode, wherein the processor alsosupports one or more higher ring operating modes, as well as a normalexecution mode in at least the ring 0 operating mode; and computerreadable program code to protect usage of a subset of the softwareenvironment using the OSNK; wherein the computer readable program codeto generate the OSNK comprises computer readable program code togenerate the OSNK based at least in part on an identification of the OSnub and a master binding key (BK0) of the platform; and wherein theoperation of protecting usage of a subset of the software environmentcomprises at least one operation selected from the group consisting of:encrypting a value while operating in isolated execution mode; anddecrypting an encrypted value while operating in isolated executionmode.
 20. The computer program product of claim 19, wherein theidentification comprises a hash value of at least one item selected fromthe group consisting of the OS nub and a certificate representing the OSnub.
 21. The computer program product of claim 19 wherein the computerreadable program code for protecting usage comprises: computer readableprogram code for encrypting the subset of the software environment usingthe OSNK; computer readable program code for storing the encryptedsubset; and computer readable program code for decrypting the encryptedsubset from the storage using the OSNK.
 22. The computer program productof claim 19 wherein the computer readable program code for protectingusage comprises: computer readable program code for encrypting a firsthash value of the subset of the software environment using the OSNK, theencrypted first hash value being stored in a storage; computer readableprogram code for decrypting the encrypted first hash value of the subsetof the software environment using the OSNK, the encrypted first hashvalue being retrieved from the storage; and computer readable programcode for comparing the decrypted first hash value to a second hash valueto generate a compared result, the decrypted first hash value beingretrieved from the storage, the compared result indicating whether thesubset of the software environment has been modified.
 23. The computerprogram product of claim 19 wherein the computer readable program codefor protecting usage comprises: computer readable program code forencrypting a first hash value of the subset of the software environmentusing the OSNK, the encrypted first hash value being stored in astorage; computer readable program code for encrypting a second hashvalue using the OSNK; and computer readable program code for comparingthe encrypted first hash value to the encrypted second hash value togenerate a compared result, the encrypted first hash value beingretrieved from the storage, the compared result indicating whether thesubset of the software environment has been modified.
 24. The computerprogram product of claim 19 wherein the computer readable program codefor protecting usage comprises: computer readable program code fordecrypting a protected private key to generate a private key using theOSNK; computer readable program code for generating a signature of thesubset of the software environment using the private key, the signaturebeing stored in a storage; and computer readable program code forverifying the signature to generate a modified/not modified flag using apublic key, the signature being retrieved from the storage, themodified/not modified flag indicating whether the software environmenthas been modified.
 25. The computer program product of claim 19 whereinthe computer readable program code for protecting usage comprises:computer readable program code for generating a manifest of the subsetof the software environment, the manifest being stored in a storage;computer readable program code for generating a manifest signature ofthe manifest using a private key, the private key being decrypted usingthe OSNK, the manifest signature being stored in the storage; computerreadable program code for verifying the manifest signature to generate asignature verified flag using a public key, the manifest signature beingretrieved from the storage; and computer readable program code forverifying the manifest to generate a manifest verified flag, themanifest being retrieved from the storage, the manifest verified flagand the signature verified flag being tested at a test center, the testcenter generating a pass/fail signal, the pass/fail signal indicatingwhether the subset of the software environment has been modified. 26.The computer program product of claim 19 wherein the subset of thesoftware environment comprises a registry of an operating system. 27.The computer program product of claim 19, wherein the BK0 is generatedat random on a first invocation of a processor nub.
 28. A systemcomprising: a processor capable of operating in an isolated executionmode in a ring 0 operating mode, wherein the processor also supports oneor more higher ring operating modes, as well as a normal execution modein at least the ring 0 operating mode; storage response to theprocessor, the storage storing at least a subset of a softwareenvironment to run on the system: an operating system (OS) nub; a keygenerator to generate an operating system nub key (OSNK) unique to theOS nub, based at least in part on an identification of the OS nub and amaster binding key (BK0) of the system; and a usage protector coupled tothe key generator to protect usage of a subset of the softwareenvironment using the OSNK; wherein the operation of protecting usage ofa subset of the software environment comprises at least one operationselected from the group consisting of: encrypting a value whileoperating in isolated execution mode; and decrypting an encrypted valuewhile operating in isolated execution mode.
 29. The system of claim 28,wherein the identification comprises a hash value of at least one itemselected from the group consisting of the OS nub and a certificaterepresenting the OS nub.
 30. The system of claim 28 wherein the usageprotector comprises: an encryptor to encrypt the subset of the softwareenvironment using the OSNK, the encrypted subset being stored in astorage; and a decryptor to decrypt the encrypted subset using the OSNK,the encrypted subset being retrieved from the storage.
 31. The system ofclaim 28 wherein the usage protector comprises: an encryptor to encrypta first hash value of the subset of the software environment using theOSNK, the encrypted first hash value being stored in a storage; adecryptor to decrypt the encrypted first hash value using the OSNK, theencrypted first hash value being retrieved from the storage; and acomparator to compare the decrypted first hash value to a second hashvalue to generate a compared result, the compared result indicatingwhether the subset of the software environment has been modified. 32.The system of claim 28 wherein the usage protector comprises: a firstencryptor to encrypt a first hash value of the subset of the softwareenvironment using the OSNK, the encrypted first hash value being storedin a storage; a second encryptor to encrypt a second hash value usingthe OSNK; and a comparator to compare the encrypted second hash value tothe encrypted first hash value to generate a compared result, theencrypted first hash value being retrieved from the storage, thecompared result indicating whether the subset of the softwareenvironment has been modified.
 33. The system of claim 28 wherein theusage protector comprises: a decryptor to decrypt a protected privatekey to generate a private key using the OSNK; a signature generatorcoupled to the decryptor to generate a signature of the subset of thesoftware environment using the private key, the signature being storedin a storage; and a signature verifier to verify the signature togenerate a modified/not modified flag using a public key, the signaturebeing retrieved from the storage, the modified/not modified flagindicating whether the subset of the software environment has beenmodified.
 34. The system of claim 28 wherein the usage protectorcomprises: a manifest generator to generate a manifest of the subset ofthe software environment, the manifest describing the subset of thesoftware environment, the manifest being stored in a storage; asignature generator coupled to the manifest generator to generate amanifest signature of the manifest using a private key, the private keybeing decrypted using the OSNK, the manifest signature being stored inthe storage; a signature verifier to verify the manifest signature togenerate a signature verified flag using a public key, the manifestsignature being retrieved from the storage; and a manifest verifier toverify the manifest to generate a manifest verified flag, the manifestbeing retrieved from the storage, the manifest verified flag and thesignature verified flag being tested by a test center, the test centergenerating a pass/fail signal indicating whether the subset has beenmodified.
 35. The system of claim 28 wherein the subset of the softwareenvironment comprises a registry of an operating system.
 36. The systemof claim 28, wherein the BK0 is generated at random on a firstinvocation of a processor nub.
 37. The system of claim 28, furthercomprising: a memory responsive to the processor, the memory to includean isolated memory area, the isolated memory area to be accessible tothe processor in the isolated execution mode and inaccessible to theprocessor in the normal execution mode; and the isolated memory areaoperable to receive the OS nub during a boot process.
 38. An apparatusaccording to claim 1, wherein: the platform comprises a memoryresponsive to the processor, the memory to include an isolated memoryarea, the isolated memory area to be accessible to the processor in theisolated execution mode and inaccessible to the processor in the normalexecution mode; and the isolated memory area operable to receive the OSnub during a boot process.
 39. A method according to claim 10, wherein:the platform comprises a memory responsive to the processor, the memoryto include an isolated memory area, the isolated memory area to beaccessible to the processor in the isolated execution mode andinaccessible to the processor in the normal execution mode; and themethod further comprises loading the OS nub into the isolated memoryarea during a boot process for the platform.
 40. A computer programproduct according to claim 19, comprising: computer readable programcode to load the OS nub into an isolated memory area of the platformduring a boot process for the platform, the isolated memory area toreside in a memory responsive to the processor, the isolated memory areato be accessible to the processor in the isolated execution mode andinaccessible to the processor in the normal execution mode.